Cyclodextrin is known to form complexes with certain materials. In many compositions, cyclodextrin is used as a carrier for active materials and thus it is desirable to form complexes between cyclodextrin and the active materials in order for the cyclodextrin to act as a carrier for the active materials. This is especially prevalent in the pharmaceautical area, where cyclodextrins have been traditionally used as carriers to deliver active materials. However, when cyclodextrin is used as a carrier for active material and is strongly complexed with the active material, the cavities of the cyclodextrin molecules are filled such that the cyclodextrin is not available to complex with other molecules.
Surfaces, especially household surfaces such as fabrics, countertops, and the like, often contain unwanted molecules, such as malodorous molecules. Cyclodextrin molecules are capable of capturing unwanted molecules from surfaces; however, cyclodextrin compositions used to treat surfaces containing unwanted molecules must have cyclodextrin that is available to complex with the unwanted molecules in order to capture and remove the unwanted molecules from the surface being treated. Compositions have been disclosed that are useful for controlling malodor on surfaces, wherein the compositions comprise uncomplexed cyclodextrin. For example, U.S. Pat. No. 5,942,217 issued Aug. 24, 1999 to Woo et al. teach compositions for controlling malodor on surfaces wherein the compositions can comprise uncomplexed cyclodextrin and materials that are cyclodextrin-compatible, such as cyclodextrin-compatible surfactants and cyclodextrin-compatible antimicrobial actives. The materials in these compositions are selected such that they do not complex with cyclodextrin in solution, thus providing available, uncomplexed cyclodextrin in solution to capture the malodor from the treated surfaces. The cyclodextrins suitable for use in the compositions disclosed in the '217 patent include derivatized cylcodextrins such as hydroxyalkyl cyclodextrins and methylated cyclodextrins. Woo et al. teach that preferred hydoxyalkyl cyclodextrins have a degree of substitution of from about 1 to about 14, and more preferably from about 1.5 to about 7, wherein the total number of OR groups per cyclodextrin is defined as the degree of substitution. Woo et al. further teach that preferred methylated cyclodextrins have a degree of substitution of from about 1 to about 18, and more preferably from about 3 to about 16.
It has thus been desired to develop optimized cyclodextrin compositions that exihibit improved performance in capturing unwanted molecules, especially malodorous molecules, by selecting appropriate cyclodextrins for: use in the compositions.